A second person, the “inquirer,” is shown a list of items the respondent may be looking at — say a dog. The inquirer then clicks on questions to narrow down the object’s identity — such as “Is the object an animal?”

The respondent answers simply by looking at one of two flashing lights on his computer screen — one for “yes” and one for “no.”

The action sends a response from the respondent’s brain activity to a magnetic coil behind the inquirer’s head, but only a “yes” response will generate enough energy to cause the inquirer to believe he’s seen a flash of light.

It’s a phenomenon called a phosphene — seeing light without light actually entering the eye.

Five pairs of people played 20 rounds of the game — ten using an operational brain-to-brain link and ten where the subjects didn’t know the link was turned off.

The scientists found when the link worked, subjects got the answers right 72% of the time compared to just 18% of the time when the link was shut off.

The scientists believe it is the most complex brain-to-brain experiment ever conducted. It was underwritten in part by a one million dollar grant from the W.M. Keck Foundation and their results have been published in the journal PLOS One.